2.2 The cognitive interview

The cognitive interview was developed for the interview with cooperative interviewees, be they witness, victim, or suspect, and basically it's a collection of tools, on a tool belt, that are trained to the police, and all help to aid certain areas of memory. Now originally the cognitive interviews consisted of 4 primary techniques.

The first technique is a simple technique, it's simply telling the witness to tell me absolutely everything they can remember; don't leave anything out, don't edit anything. The reason why this simple technique, basically to tell someone 'tell me everything', is that we know that even the most cooperative adult does not spontaneously report everything that they remember. When they remember something, when they retrieve it, they make a decision. Do I tell the person I'm talking to, or do I withhold it? So this simple technique of tell me everything stops witnesses and victims and suspects withholding information.

Now, people may withhold information for a large number of reasons, one reason is they think well, it's not important information, but the general public do not know what is important to the police. They might withhold information because they're not sure about it - oh, did I see that or did I not - and there's lots of research looking at the correlation between how confident someone is and actually how accurate they are, and indeed, confidence is instead a personality measure rather than an accuracy measure. Someone may withhold something because they feel the police already know, they've interviewed other people, there was CCTV there, but what we train the police to do is explain to every witness that when they are solving a crime they are piecing it together. Every information they get - whether it's from CCTV, whether it's from other witnesses, whether it's from the interview with a suspect - they piece all this information together like a jigsaw puzzle, and they basically try and make sense of all that information to try and find out the two key investive questions - what happened and who done it?

So just because an individual might believe the police already know, it's important for them to report it too, because it might be the key final piece to that jigsaw puzzle, to solving what has happened. So, the report everything instruction is very very very essential to getting the maximum quantity of detail from a witness or victim or suspect of crime.

The second technique is what we call context reinstatement. This gets witnesses to think back in their mind's eye the environment of where the crime actually occurred. It's very much like, you know if you've lost a set of keys or a pair of glasses, and you try and think in your head, you create an image of where you thought you last saw them, whether it's your place of work, your home, and you try and think 'where was it?' and you visualise that place in your head and you think of where the keys were. Very similar, what we try and do is we get our witness or victim to either close their eyes, or look at the floor, we don't want them to be too distracted, and we get them to create an image in their mind's eye of that scene. And it's quite easy to do, all we get them is to start thinking about things, and we say some basic phrases, we say for example:

'I want you to close your eyes, get a clear, clear picture of the scene in your head. Think about everything that you can remember in that scene. Get a clear picture of it. Think about the layout of the scene. Think about all the objects that were there. Think about all the colours that you can remember at the scene. Think about all the sounds that you remember hearing. Get a clear picture of all the people that were there. Then in your own time and your own pace, tell me everything you can remember about that scene.'

And that's getting people to slow down, to think about the scene in their head, and to create that image in their mind's eye, and we know through research that is very helpful for memory retrieval.

Another of the basic 4 cognitive techniques is called the reverse the temporal order of recall technique, and this basically gets people to think about the event in a variety of ways. So we get people to either go backwards from the last thing they remember to the first, or from the most memorable aspect of the event and going backwards and forwards in time. Now the reason why this is important is that people from a very young age develop scripts in memory, and the primary reason we do that is because we dislike the unknown. Everyone has been in the situation where you go in somewhere new, it may be a new place, a new restaurant, and you're a bit unsure of what it's like, so you ring someone up who's been there before and go 'What's it like? How smart is smart, what are you wearing?'. That is typical fear of the unknown and because we all fear the unknown, from the age of about 3 we start developing rules and regulations in life. What typically happens in a restaurant? What typically happens in a dentist?

So, people develop these scripts. Now, most crimes, which are one-off events, tend to be - unless it's domestic violence or child abuse - but most crimes like murder or an armed robbery, or a bystander, a witness... it's a one-off event. However, these one-off events, what we call episodic memory, is embedded into someone's routine, and so therefore when we get people to report an event, they might just report what normally happened on a day, what typically happens on the day, but what we really want them to do is remember what happened on the specific day. Rather than relying on their normal routines, we want to know exactly what happened on that particular day. And so getting someone to go backwards and form the most memorable aspects of the event and going backwards and forwards in time, it gets people to go back to that original memory of what actually occurred.

The reverse order recall instruction is also very useful for trying to detect deceit, of course unfortunately within investigations people do lie, and there has been a whole body of research looking at methods of detecting deceit. Now when people lie they rehearse their lies. And typically people will rehearse their lies in a chronological order, and therefore if we get people to go backwards in time, this therefore really is tricky for someone who is lying, and so research by someone called Albert Vrij, he has examined the uses of cognitive interview with people who are lying, and he find that it's very difficult for people to lie when the cognitive interview is used in an interview scenario.

The final technique, the fourth one of the original four is something called the change perspective technique. Now people again are also very ego-centric - we're very me me me me me - which is fine when you get a witness, maybe of a very traumatic event to recall an event. You know, we have weapon focus effect and people are there, you know, going god 'this happened', 'that happened', and so of course understandably they report it from their own view point their own perspective. This technique, which is often used further on in the interview, gets people to think about the event from another perspective. So, for someone else who was at the scene. For example, you get people to think about the event in the shoes of, it's almost like they're in a spotlight, and you get that person to isolate that particular memory about the person with the gun, like they're in a spotlight like on a stage, and we just want them to report everything they remember about that particular individual. And this gets people to start thinking about, puts them in the shoes of, another individual at a scene, maybe even the perpetrator, though it does depend on how traumatising the type of event. For example, we wouldn't get someone who has suffered a serious sexual assault, to put themselves in the shoes of a perpetrator. However when they witness the crime as an eyewitness rather than a victim themselves, then that is a very useful technique, to get them to think about the bigger picture. It really helps people to think outside the box, and in lots of scenarios in life people have to think outside the box, and this is a way of doing it - getting people instead of thinking about their role in an event, think about the role of other people - and that's another way to trigger memory.

Those four techniques form the original cognitive interview, which were originally back in the early 80s given to police officers to use as and when they wished within their normal interviewing. However, research examining how police typically interview in the field was quite shocked that the police did not conform to what we would say is good, appropriate interviewing to get maximum quantity and quality of information from people. We know, through research, the best way to interview someone is to start with what we say an open question - tell me everything - we get a free recall for someone, and what that means is someone can recall in a free manner, recall in any way they want, and they basically recall as much as they want, and they have their own time. When that free recall has finished, then what we do is we break that free recall up, and we ask questions about topic areas, in the order that person's remembered it, again using open questions.

It seems to go against common sense, but to get information you do not need to ask lots and lots of questions, because every time you ask a question you are stopping that interviewee speaking. So really what you are trying to do is basically get information from someone without asking as many questions... what you've got to do is get information from someone with asking the fewest questions possible. What we often say is the thing, the interview, that a police officer is striving to achieve is the questionless interview, because every time a police officer asks a question, there is the possibility of contamination of human memory. And so what we're striving for when we're training and teaching police officers is almost to try and get as much information as possible without contaminating memory, and so therefore that sort of 'golden ball in the sky' that they are trying to achieve is the questionless interview.

It doesn't exist, it'd be almost impossible to have a questionless interview, however if that's what they're looking for, every time a police officer asks a question, they're really trying to concentrate on what is the value of that question. Because in everyday communication, we ask hundreds of questions, we ask questions we don't really want the answer to - 'are you OK'? You know, really, we normally in everyday communication ask the question 'are you OK?', we don't want people to go 'Actually not, I'm not OK' and go into their ailments. We really just want out of courtesy 'Yes, we're fine', and so in normal conversation we ask questions which are very leading - married, family, children?

We ask questions which we don't want the answer to, we over talk people, and so we can't rely on our normal communication skills in a police interview, because it's not an information gathering communication normally talking to people, in a perhaps, you know, over dinner or in a pub scenario. And so, we have to almost go against some of our normal conversational rules. One of our conversational rules, some have called the maximum of quantity, we learn from a very young age that speaking in lots of detail is very rude. So for example, I have a 5 year old son, and at the moment we're teaching turn taking - it's mummy and daddy's turn at the moment to speak, it's your turn next. And so we learn from a very young age that giving lots of detail is not needed in a normal conversation, however in a police interview that's what we're asking witnesses to do - give us detail.

So if I'm asking a 40 year old, who has learnt from the age of 3 that detail is not required, we're getting people to break normal conversational rules. We're also getting the interviewers to break normal conversational rules. So what we found in what we call the typical standard police interview, is that police officers tended because they had no training prior to 1992 in Britain, they had no training how to do this very complex psychological task - to interview, to gather information - they were relying on their normal conversational skills, and those normal conversation skills aren't information gathering approaches. So we suddenly realised as psychologists that we had to start training police officers not just to use techniques to enhance memory, but we had to teach them techniques which basically got good communication skills for information gathering approaches.